Polyps are abnormal growths rising from the lining of the
large intestine (colon or rectum) and protruding into the
intestinal canal (lumen). Some polyps are flat; others have a
Polyps are one of the most common conditions affecting the
colon and rectum, occurring in 15 to 20 percent of the adult
population. Although most polyps are benign, the relationship of
certain polyps to cancer is well established.
Polyps can occur throughout the large intestine or rectum,
but are more commonly found in the left colon, sigmoid colon, or
What are the symptoms of polyps?
Most polyps produce no symptoms and often are found incidentally
during endoscopy or x-ray of the bowel. Some polyps, however,
can produce bleeding, mucous discharge, alteration in bowel
function, or in rare cases, abdominal pain.
How are polyps diagnosed?
Polyps are diagnosed either by looking at the colon lining
directly (colonoscopy) or by x-ray study (barium enema).
There are three types of colorectal endoscopy: (1) rigid
sigmoidoscopy, (2) flexible sigmoidoscopy and (3) colonoscopy.
Rigid sigmoidoscopy permits examination of the lower six to
eight inches of the large intestine. In flexible sigmoidoscopy,
the lower one-fourth to one-third of the colon is examined.
Neither rigid nor flexible sigmoidoscopy requires medication and
can be performed in the doctor's office.
Colonoscopy uses a longer flexible instrument and usually
permits inspection of the entire colon. Bowel preparation is
required, and sedation is often used.
The colon can also be indirectly examined using the barium
enema x-ray technique. This examination uses a barium solution
to coat the colon lining. X-rays are taken, and unsuspected
polyps are frequently found.
Although checking the stool for microscopic blood is an
important test for colon and rectal disorders, a negative
test does NOT rule out the presence of polyps. The discovery
of one polyp necessitates a complete colon inspection, since at
least 30 percent of these patients will have additional polyps.
Do polyps need to be treated?
Since there is no fool-proof way of predicting whether or not a
polyp is or will become malignant, total removal of all polyps
is advised. The vast majority of polyps can be removed by
snaring them with a wire loop passed through the instrument.
Small polyps can be destroyed simply by touching them with a
coagulating electrical current.
Most colon examinations using the flexible colonoscope,
including polyp removal, can be performed on an outpatient basis
with minimal discomfort. Large polyps may require more than one
treatment for complete removal. Some polyps cannot be removed by
instruments because of their size or position; surgery is then
Can polyps recur?
Once a polyp is completely removed, its recurrence is very
unusual. However, the same factors that caused the polyp to form
are still present. New polyps will develop in at least 30
percent of people who have previously had polyps. Patients
should have regular exams by a physician specially trained to
treat diseases of the colon and rectum.